New Trends on Integrity, Reliability and Failure IRF 2016 1 PAPER REF: 637702 NUMERICAL EVALUATION OF THE BEHAVIOR OF TUBULAR COLUMNS IN THE CONNECTIONS TO I BEAMS WITH WELDED REVERSE CHANNEL Luís Magalhães 1(*) , Calos Rebelo 2 , Sandra Jordão 2 1 ISISE, Polytechnique Institute of Castelo Branco, Castelo Branco, Portugal 2 ISISE, Department of Civil Engineering, University of Coimbra, Coimbra, Portugal (*) Email: lmmbmagalhaes@ipcb.pt ABSTRACT This paper presents results of numerical study on the behaviour of tubular columns in the connections to I beams with U-profiles, effected on the basis of a parametric variation of the most significant characteristics of tubular profiles. The parameters considered are the thicknesses, the widths and the diameters of the tubular columns, the filling with concrete. The main purpose is the characterisation of the nonlinear behaviour of this type of steel joints. The results of the parametric study with numerical models allow correlate the parameters considered with the structural behaviour of the connection, defined by the resistance, the stiffness and the rotation capacity and calibrate the experimental tests. The numerical models are developed with the software LUSAS. Keywords: tubular columns, reverse channel, numerical models, resistance, stiffness, rotation capacity. INTRODUCTION When compared with other steel shapes, tubular profiles show a privileged structural behaviour due to their ability to withstand axial loads, bending in several directions and torsion, besides considerable advantages in terms of maintenance and aesthetics. The welded reverse channel connection is a good solution since it allows for a bolted joint between I beam to hollow column. Furthermore, this type of joint detail has a reasonable construction cost, is easy to implement and possesses large ductility through the deformation of the U web panel combined with the tubular column. Traditional solutions, like bolted and welded joints, or are impractical because there was no access to the interior of the tubular profile or become expensive due to the welding process at work. Due to this fact, a lesser effort has been directed to research on these typologies, and less comprehensive methods of analysis or code formulation exists for their design. Eurocode 3 provides some rules for welded connections between tubular profiles, but not for bolted connections. However, due to its strategic importance, this topic has had several significant contribution in the last decade. Among those some research initiative from the “Comité International pour le Développement et l’Étude de la Construction Tubulaire” CIDECT stands out, aiming at the development of an unified design approach for steel joints by extending the field of application of the Eurocode 3 component method. The main purpose of this investigation is the characterisation of the nonlinear cyclic behaviour of steel joints with welded reverse channel welded to hollow section columns and bolted to I profile beams, depicted in Fig. 1.